I bought a house that has a gas boiler with circulating hot water. It previously was a steam system and I have all of the original cast iron radiators in use with the system. The pipes coming out of the boiler are 2" in diameter and the pipes branching out to the radiators look like they are 1 1/2. I was wondering if it would be worth my while to change all of the piping and swap the radiators for baseboard. My thought was that the amount of water that I have to heat now in the larger pipe is causing my boiler to run more. Has anyone had any experience with making this change? Can anyone let me know what kind of savings I would see if I made the change to 3/4 pipe with baseboard heat? I plan on keeping the house for at least 5 more years and I want to see if spending the money on this upgrade would pay. Thanks!